Summary

Total Knee Arthroplasty without patellar resurfacing represents a non-significant number of increased re-intervention in selected patients.

Abstract

Background

Controversies exist about patellar resurfacing in total knee arthroplasty (TKA). Last international register publications and meta-analyses show that patellar resurfacing would decrease the risk of revision.

Purpose

To evaluate the risk of re-intervention at midterm follow-up for any reason in patients who underwent TKA with or without patellar resurfacing. We hypothesize that the absence of a patellar component will likely have higher reinterventions.

Methods

Retrospective study in 281 TKA, which underwent surgery in the same center between August 2015 and July 2019. Mean age 68,5 yo ; 37% male y 63% female. The groups were 136 (48,4%) knees with patellar resurfacing (PR) and 145 (51,6%) knees without patellar resurfacing (WPR). The decision of patellar resurfacing was determined by the presence of patellar osteoarthritis or patellar pain. Inclusion criteria were >18 yo and primary posterior stabilized knee replacement. Patients who underwent revision surgery or had a follow-up of < 24 months were excluded. Re-intervention after index surgery, diagnosis of reintervention, and operative time were identified through the hospital database. Statistic analysis was done with Statplus version 8.0.3. The hospital ethic board approved the study.

Results

The mean follow-up was 5,1 years for the PR group and 4,3 years for the WPR group; no demographic differences were found. Eight patients (6%) from the PR group underwent re-intervention: 3 mobilizations under anesthesia (MUA), four infections (1 two-stage revision, three open debridements and polyethylene exchange (ODPE)), and one dehiscence. 12 patients (8%) from the WPR group underwent re-intervention: 4 MUA, five infections (3 two-stage revisions, 2 ODPE), one dehiscence, and two revisions for patellar resurfacing (>18 months). The cause of patellar component revision for both patients was anterior pain. We did not find statistical differences for the total number of reintervention (p=0,41), nor the infection rate (2,9% versus 3,4%, p=0.8). The Odds Ratio for aseptic re-intervention was 1,92 for the WPR group, 95% confidence interval of 7,86-0.47, non-statistical significance. The mean surgery time was 8 minutes faster for the WPR group (p=0,003).

Conclusions

TKA without patellar resurfacing represents a non-significant number of increased re-interventions. We estimated that results in the midterm follow-up do not limit the selective patellar component replacement.